My network has a webserver with multiple IP's that talks to a
database machine (not outside the firewall, but that isn't
important). It uses the primary IP. A quick NETSTAT showed that.

Whether you can force the client to use a specific IP to communicate
with a database server - I don't know. But you don't need to worry
about that, the primary IP is used, so let that through.

As I mentioned above, if you bring up a command prompt on the client
machine (after an ODBC connection to the database machine has been
made), and run the command "netstat -n", you'll see what IP on your
client is doing the talking.

(If anyone else on this list can answer the "force the client to use
a specific IP" question, share the answer!)

Quick question: I want to open up a connection through our firewall
from an
IIS server with multiple IP's each mapped to individual webs to a SQL
server
on the other side. What I'm wondering is will the web server use
it's
primary IP to make the connection to the SQL server? I only want to
allow
the one IP through the firewall.